Dental slab



Nov. 27, 1934. J. B. EARMAN 5 DENTAL SLAB Filed April 4, 1933 Patented Nov. 27, 1934 UNITED STATES PATENT} OFFICE.

DENTAL SLAB John Burke Earman, West Palm Beach, Fla.

Application April 4, 1933, Serial No. 664,436

3 Claims.

My invention relates to slabs used in dentistry for the preparation of fillings andother similar materials used in the art of dentistry and it particularly has for its object to provide a slab which may be given, at little or no expense, a fresh working surface at each operation without using up the slab or wearing out its working face.

Further, the invention has for an object to provide a dental slab with means temporarily to re- '10 tain a film or sheet of suitable material, such as celluloid, wax-paper, etc., the slab being made of any suitable hard material such as cement, stone or in fact almost any material which will give a hard working surface.

Further, it is an object to provide a slab over whose working face a thin sheet is removably held by a frame which has provisions cooperating with the slab for drawing the sheet taut and, by the weight of the frame supplemented by friction, holding the sheet in place taut while being used.

Other objects will in part be obvious and in part be pointed out hereinafter.

To the attainment of the aforesaid objects and ends, the invention still further resides in the novel details of construction, combination and arrangement of parts, all of which will be first fully described in the following detailed description, then be particularly pointed out in the appended claims, reference being had to the accompanying drawing, in which:

Figure 1 is a perspective view of my invention.

Figure 2 is a vertical longitudinal section of the same.

Figure 3 is a vertical longitudinal section showing the position of the parts when a new sheet is about to be secured to the slab.

In the drawing in which like numerals of reference indicate like parts in all of the figures, 1 represents the slab composed of cement, stone or other suitable hard material capable of taking on a hard surface which constitutes the working face 2 of the slab.

The slab has an ofiset portion 3 and a base surface 4, the latter being engaged by the skirt 8 of the frame 9 when in the assembled position.

The slab has a gutter or groove around the same and a rib 6 the latter entering the groove 10 of the frame 9. The frame 9 also has a rib 11 which is adapted to be received by the gutter or groove 5 of the slab 1 when the parts are assembled. The film or sheet 7 is laid over the working face 2 of the slab and then the frame 9 is placed on the same and pushed down from the position shown in Figure 3 to the position shown in Figure 2. This folds over the sheet and clamps its marginal portion between the slab and the frame. V

In lowering the frame 9 from the position shown in Figure 3 to fit the film to the slab, the lower border of the skirt 8 will grip the film 7 at the rib 6 on the slab. As the frame passes down around the slab the film is at an angle from the margin of the working face 2 of the slab to the border of the rib 6. Now as the frame is moved 5 farther down the rib 11 engages the film (its margin now being held by a skirt 8) and forces the film tight to the border of the slab, thus making the film tight on the face of the slab and creating a smooth working surface.

The frame is preferably made of heavy metal such as lead, non-corrosive iron, or the like, so that the weight of the frame plus the friction of the parts in contact will be sufiicient to hold the sheet taut over the working face 2.

A new sheet is used at the commencement of each operation so that in this way a fresh working surface is given the slab each time it is used.

The frame 9 may be provided with a knob 12 at each end to permit its easy withdrawal from the slab.

From the foregoing description, taken in connection with the accompanying drawing, it is thought the construction, operation and advantages of my invention will be clear to those skilled in the art to which it relates.

What I claim is:

1. An appliance of the character described, comprising the combination with a slab having a working face, and having stepped sides and ends, the step having a downwardly cut V-shaped groove, a film placed over the working face and a frame embracing said stepped sides and ends of said slab and the marginal portion of the film, said frame having a downwardly directed V- shaped rib to enter said groove, said frame having a weighted and a skirt portion, the weighted portion serving to hold the frame down and effect the holding of the film taut over the working face of the slab, the upper face of said frame being downwardly beveled away from the slab.

2. A dental appliance of the character described comprising a slab provided with a raised work supporting body and an outstanding base portion, said outstanding base portion being provided with a vertical channelway extending entirely around the said block, a sheet of flexible material for disposition over the top surface of the block, a frame provided with a depending rib, said frame being adapted to snugly engage material, a frame for snug slidable fit over the side walls 6f the slab portion and being provided with 2. depending rib for nested disposition in the channel when the frame is urged downwardly and into the base to clamp the sheet in a U-shaped bend, said frame being provided with a depending apron outwardly offset with respect to the rib and adapted to snugly clamp the edge portion of the sheet against the side walls of the said base portion.

" JOHN BURKE EARMAN. 

